Alright guys. This has almost become a tradition for me since Mountain Lion - to update to Apple's latest and greatest OS and run some game benchmarks - to see what, if anything, has changed. The one thing that's remained constant is the specs of my iMac - the 2.9GHz i5, 8GB RAM, 1 TB HD, 512MB nVidia Geforce GT 650M gpu. This time, we're talking OS X 10.10 Yosemite. I'm going to largely focus on games which use OpenGL 4.x, because early reports are showing minimum FPS doubling, which seems rather exciting, especially for those of us who play action games online. http://forums.macrumors.com/showthread.php?t=1734820&highlight=tomb+raider+benchmark&page=3 I'll start with Unigine's Heaven, which runs OpenGL 4.1 and hardware tessellation on nVidia Kepler GPUs and newer: Here are the results (default res for Heaven on my Mac is 1024 x 576) Test one Med qual Tess Normal All Options On AA off ______________ 34.1 FPS (8.8 min, 61.2 max) Test two Med qual Tess disabled All Options On AA 4x ______________ 36.4 FPS (13.1 min, 61.4 max) These compare favorably to the tests I ran a year ago when Mavericks was first introduced: http://forums.macrumors.com/showthread.php?t=1658798 I've added a new test this time, including 4x AA and the lowest tessellation, just to see the impact it has. Test three Med qual Tess Moderate All Options On AA 4x ______________ 29.7 FPS (13.5 min, 61.5 max) So, the latest version of Heaven running the latest version of OS X is showing not a minimum frame rate boost, but a maximum frame rate boost. It's also showing in this benchmark lower minimums in one setting, and higher minimums in the other. Let's move on. I'm going to run a simplified set of benchmarks for Batman Arkham City: 1024 x 768 Min - 28 Max - 60 Ave - 49 1920 x 1080 Min - 25 Max - 60 Ave - 43 Like last time, the only difference between these runs is the resolution: Last Year's #s on Mavericks 1024 x 768 Min - 19 Max - 60 Ave - 48 1920 x 1080 Min - 7 Max - 56 Ave - 38 So, quite an interesting story here in Arkham City! At 720p, the game ran a dramatic increase in minimum frame rates. At 1080p, the minimum frame rate nearly quadruples (from 7 to 25). I'm curious to know if this delta would increase as the resolution increases. My 21.5" iMac maxes out at 1080p, so maybe owners of 27" models or Macbook Pro retinas/Mac Pros could chime in with their higher resolution experience. Now, let's look at Tomb Raider, an OpenGL 4.1 game which features a built-in benchmarking tool: Default settings at 1344 x 756 Min - 45.3 Max - 62.9 Avg - 56.5 Back in March, when I ran the benchmark in Mavericks I got 55 avg. Not a huge improvement. Hopefully, this will serve as a beginning of a discussion of performance with regard to Yosemite and modern games! Enjoy!